% BUILD VECTORS OF X Y Z COORDINATES ON THE SURFACE OF THE SPHERE AND
% COMPUTES THE AREA OF EACH GRID CELL
function[x,y,theta,dtheta]=long_lat_coord2D(n,R)
dtheta=2*pi/n;
theta=[0:dtheta:2*pi-dtheta];
index=0;
for j=1:n
    index=index+1;
    x(index)=R*cos(theta(j));
    y(index)=R*sin(theta(j));
end
